Recently, V2V communication, which is mainly used for exchanging road safety-related information among vehicles, has been rapidly developed. For example, a vehicle can inform another vehicle of its own speed, position, driving direction, braking condition and the like. Therefore, a driver can be notified in advance through the V2V communication, for example, by receiving warning information indicating that a distance between vehicles is too small or there is an accident ahead, such that the driver may have enough time to take actions, thereby reducing occurrence of accidents.
Due to the characteristic of the V2V communication, there is a high demand for rapid transmission of road safety information. Therefore, a method for exchanging information among vehicles rapidly and reliably is required.